June 3, 2012
I still argue with the voice on my GSP. Don’t look at me that way: You do it, too! The voice has a British accent; we call her Petula. And I still argue when I want to stay on I-95 and she tries to send me onto US-1. But I do have a little more respect for her — or, at least, for the device — now that I’ve read Chad Orzel’s book “How to Teach Relativity to Your Dog.”
Orzel, a professor who also wrote “How to Teach Physics to your Dog,” explains in this more recent book that the technology of global positioning systems relies on a principle of the theories of relativity first formulated by Albert Einstein. A principle of the special theory of relativity holds that a clock that is in motion will “tick” increasingly more slowly as the speed of its motion increases. The general theory of relativity, on the other hand, holds that a clock runs faster the higher it is — that is, the greater its altitude in the gravitational field.
The atomic clocks aboard the GPS satellites speed up because of their altitude and slow down because of the speed at which the satellites orbit the earth. At the altitude of those satellites, the clocks are quickened more than they are slowed, but they are still keeping time at a different rate than clocks on the surface of the earth. Each satellite emits a radio signal with the time on its atomic clock. The GPS unit picks up two or three of those signals, calculates the difference between the time on the satellite clock and the time on the surface of the earth, and uses that information to determine the distance to each satellite and, from that, the location of the unit on the ground.
Pretty cool, huh?
Still, I don’t read about physics because I’m interested in the practical applications so much as because I’m interested in the theories and principles. It can be mind-bending stuff, but if given enough concentration and persistence, it can lead to some moments of enlightenment about how the universe works. And studying the theories of relativity, in particular, can be an eye-opening series of reminders that things are not always what they appear to be.
Orzel’s technique in this book is to explore the special and general theories of relativity, and some other matters, as though he were discussing them with his real-life dog, Emmy. This is the writer’s way of making the material more accessible to people like me, but frankly, it gets tiresome. The dog’s constant references to Orzel as “Dude” and the overworked jokes about Emmy’s appetite, disdain for cats, and fixation with chasing rabbits, grow old pretty quickly. And the premise crumbles as the dog begins to talk about physics as if she were a graduate student at Princeton.
I think anyone who picked up this book thinking that the dialogue with the dog, and the use of dog-world examples, would make physics easier to understand would be disappointed. Orzel’s explanations are clear, but he could have been just as clear without the input from the dog. More important, with or without the dog, a reader won’t get much out of this book without focusing attention on it, frequently stopping to think hard about what Orzel has just written, frequently re-reading paragraphs or whole sections and consulting the glossary at the back of the book.
Both the special and general theories of relativity depend on the idea that the laws of physics work the same for observers who are in motion and observers who are stationary, even though an event — such as a person dropping a ball from above his head to the floor at his feet on a moving train — will appear differently to the person dropping the ball and a person observing the event while standing still on the station platform.
An interesting thing that comes up again and again in Orzel’s book is the fact that researchers are still discovering implications of these theories that Einstein expounded at the beginning of the 20th century. Already Einstein’s work has led to the understanding that the mass of an object is a measure of its energy and the two properties are connected by the constant e=mc²; that time and space are expressions of the same thing; that gravity bends light; that large objects bend space; that a moving object shrinks in length in the direction in which it is moving — the faster it moves, the more it shrinks.
Orzel’s also discusses black holes, those concentrations of mass so dense that even light can’t escape their gravity; the principles behind nuclear energy — both the relatively weak energy that holds atoms together and the enormous energy that can power cities or destroy them; the discovery that the universe is expanding at a constantly increasing rate; and the likelihood that this expanding universe began as a single point that exploded in what we know call the “big bang.”
The dog? I can take or or leave her. But reading this book — some of it two or three times — was worth the energy (which, by the way, equals mass times the speed of light squared)
December 10, 2011
I’ve been reading some articles about time travel; it’s a good way to make your head spin without the aid of alcohol.
The subject came up because we watched “Happy Accidents,” with Marisa Tomei and Vincent Donofrio. In this film, released in 2000, Tomei plays Ruby Weaver, a woman chronically unlucky in her relationships with men. She thinks her luck has changed when she becomes involved with Sam Deed (Donofrio), until he tells her that he is a traveler from the future – specifically from the year 2470.
Sam claims that he saw Ruby’s picture when he was living in Dubuque, and that he traveled through time, to Brooklyn, in search of her – though he doesn’t say why. As any person would, Ruby initially thinks Sam is either joking or deranged, but Sam won’t budge off his story. Ruby is particularly disturbed by a notebook in which Sam has repeatedly sketched the face of a woman — he claims it’s Ruby’s face — and written the words Chrystie Delancey — he claims she’s his “contact,” another time traveler who was assigned to give him his orientation when he arrived in the past — that is, the present.
This tale grows quite intense; in fact, I was surprised to see it listed on IMDb as a comedy, because there’s nothing funny about it. It keeps us guessing whether we’re watching a fantasy in which Sam is telling the truth, or a tragedy in which Sam is either playing mind games with Ruby or is insane.
Underlying the story itself is the paradox that the notion of time travel to the past always poses — the question of causality. Namely, if time travel to the past were possible, would the time travelers, either by their mere presence or by their overt actions, change the course of events, change the future.
I don’t think this movie did very well at the box office, but it’s a worthwhile property. The story is compelling, Tomei and Donofrio are both magnetic, and there are strong supporting performances by Tovah Feldshuh as Ruby’s mother, Holland Taylor as Ruby’s therapist — a pivotal role, and Nadia Dajani as Ruby’s best friend.
Several years ago, I read a book entitled The Physics of the Impossible by theoretical physicist Michio Kaku. In that book, Kaku explored some ideas that have been presented over the years in science fiction literature, films, and TV shows, and organized them according to how plausible they were. As I recall, he concluded that under the known laws of physics, time travel into the past was impossible and time travel into the future was possible, but not likely to become reality for many many years. If you’d like to see a somewhat comprehensible explanation of Albert Einstein’s view of time travel, click HERE.
“The truth of our faith becomes a matter of ridicule among the infidels if any Catholic, not gifted with the necessary scientific learning, presents as dogma what scientific scrutiny shows to be false.”
Thus spake the Dominican priest Thomas Aquinas in the 13th century. Aquinas was a master of the syllogism, and his idea of scientific scrutiny was that conclusions had to be based on premises which themselves were either self evident or had been objectively demonstrated. I thought of Aquinas when I wrote a post yesterday about Albert Einstein, who was in the business of putting together premises and conclusions. In a sense, Aquinas and Einstein came at the question of the origins of the universe from opposite directions. Aquinas was a man of faith, but he believed — and sought to demonstrate in his “Summa Theologica” — that a person could arrive at the existence of a First Cause — God — through reason alone.
Einstein didn’t believe in God in the sense that Jews and Christians and Muslims do. In that sense, he didn’t believe in a god at all, no matter how hard religious folks try to hear him saying otherwise. However, Einstein’s lifetime of inquiry into the physical laws that govern the universe did lead him to speculate — forgive me if I don’t express this precisely — that somewhere beyond the seemingly endless questions about the universe must lie some force that governs it.
I recently discussed all this — Aquinas, Einstein, God, the origin of the universe — with, of all people, the actress Sandy Duncan.
By “of all people,” I don’t mean to imply that there is anything surprising about Sandy Duncan discussing such things. In fact, I gathered she gives such things quite a bit of thought and has had provocative conversations about them with her two adult sons. I only meant that I would be unlikely to talk to Sandy Duncan at all, except that she was scheduled to appear in a new play that examines the outfall that can occur when science and religion collide head-on. The actress was to play the title role in “Creating Claire” by Joe DiPietro, but she took ill, withdrew from the cast, and was replaced by another talented performer, Barbara Walsh.
DiPietro’s play begins previews tomorrow night at the cradle of new theatrical works, the George Street Playhouse in New Brunswick. The title character, Claire Buchanan, is a teacher but now works as a docent at the Museum of Earth and Sky in upstate New York. She leads visitors on the Origins of Life Tour, reciting a script that focuses on the evolution of species. The script is the brainchild of Victoria Halstead, museum director and friend of Claire – in that order, as things work out. Victoria encourages a docent to “personalize” the presentation as long as the glosses are innocuous, but Claire is no automaton, especially when a reference in the script to “random mutation” complicates her attempt to understand a fact of her own life. Claire and her husband, Reggie, have an autistic 16-year-old daughter, Abigail, and Claire has been considering how the process described by Charles Darwin could result in an individual such as Abigail. Eventually, Claire’s contemplation creeps into her talks at the museum as she suggests to visitors that the processes of nature may have been – gasp! – designed. Once that genie is on the loose, there is hell to pay, as it were.
Victoria — to be played by Lynn Cohen – puts her own belief in science and her vision for the museum ahead of friendship when she learns about Claire’s transgression. Reggie – a high school teacher who has considered his bond to Claire a “mixed marriage” only to the extent that he is an atheist and she is an agnostic — is stunned by this change of Claire’s train of thought. Disagreements over Abigail’s status have already revealed strains in the couple’s relationship; Claire’s public speculation about a “designer” pushes those strains to the breaking point.
This play, however, is not a death struggle between science and religion so much as an examination of intellectual openness and honesty. Claire is willing to at least entertain an idea that had been anathema to her but does not insist that others accept that idea. Victoria and Reggie opt to defend their “rightness,” as Duncan called it, regardless of the professional or personal consequences. The implications for contemporary political discourse may be painfully obvious.
Believe in God or not, but in the end it is Claire, and not the more “scientific” Victoria and Reggie, who seems to have heeded Einstein: “Only daring speculation can lead us further, and not accumulation of facts.”
May 17, 2010
Several decades ago, I began to make a point of reading several books each year on subjects about which I knew little or nothing — including subjects that I found repulsive. Among those subjects have been mathematics and physics, both of which bedeviled me when I had to study them in high school and college. As I have mentioned here before, at least with respect to mathematics, I have derived a great deal of satisfaction from pondering these subjects when examinations and grades are not at issue, and I have found that those who claim that there is beauty and wonder in these fields are telling the truth
That background explains why I grabbed the opportunity to review a popular biography entitled “Einstein: The Life of a Genius” by Walter Isaacson. This is a coffee table book that contains a limited amount of text in proportion to the number pages and illustrates its points with many photographs and also with facsimiles of several letters and documents. Among these are Einstein’s letter to Franklin D. Roosevelt in which the scientist advised the president to call together a group of experts to study the possibility of developing an atom bomb — something Nazi Germany was known to be doing at the time. As it happened, Einstein — a pacifist whose work in physics helped pave the way to such weapons — was considered too great a security risk to work on the project himself, what with him being a native of Germany, a socialist, and a Jew.
Isaacson records that one of Einstein’s early physics instructors described him as “an extremely clever boy,” but added, “You have one great fault: You’ll never let yourself be told anything.” It wasn’t meant as compliment, but still, this tendency as much as anything else led to Einstein’s achievements in theoretical physics. Einstein — like Isaac Newton before him — would not accept anything as settled just because it was handed on to him by authoritative sources. He wondered and questioned and “experimented” with physical phenomena such as light and motion by forming images in his mind, and he changed the world.
Einstein is a curiosity in a way, because he was one of the most widely known celebrities of his time and his name is part of our language more than 50 years after his death, and yet most of us have little or no idea what he was up to. That doesn’t matter. He deserves his place in our culture if for no other reason than his persistence in questioning even his own conclusions.